Grommet with silencer

Abstract

A grommet includes a small diameter tubular portion to which a wire harness is tightly fitted and inserted therethrough, and a large diameter tubular portion continuous to one end of the small diameter tubular portion. A silencer made of rubber is fitted within the large diameter tubular portion. The silencer includes a flat circular piece blocking a central cavity of the large diameter tubular portion. A wire harness insertion hole is provided on the flat circular piece communicating with the small diameter tubular portion of the grommet. A slit is provided from the wire harness insertion hole to an outer peripheral surface of the flat circular piece in order to insert the wire harness into the wire harness insertion hole with sideways insertion. The slit is provided with an irregularly shaped line portion to inhibit separation, configured with a keyhole-shaped or a dovetail groove-shaped line between both ends.

The invention claimed is: 
     
       1. A grommet having a silencer, wherein:
 the grommet is configured to be mounted on a wire harness routed through a through-hole in a vehicle body panel from an engine compartment side to a cabin interior side of an automobile, the grommet comprising:
 a small diameter tubular portion to which a wire harness is configured to be tightly fitted and inserted therethrough; and 
 a large diameter tubular portion continuous to one end of the small diameter tubular portion, the large diameter tubular portion provided on an outer peripheral surface with a vehicle body engagement concavity configured to be tightly fitted to a peripheral edge of the through-hole; 
 the silencer is made of rubber and is inserted into and fitted within the large diameter tubular portion, the silencer comprising: 
 a flat circular piece blocking a central cavity of the large diameter tubular portion in a direction substantially orthogonal to an axis thereof; 
 a wire harness insertion hole provided on the flat circular piece and communicating with the small diameter tubular portion of the grommet; and 
 a slit extending from the wire harness insertion hole to an outer peripheral surface of the flat circular piece in order to allow sideways insertion of the wire harness into the wire harness insertion hole, wherein
 the slit comprises: 
 an irregularly shaped line portion that defines a recess in a first opposing side of the flat circular piece that borders the slit and defines an enlargement on a second opposing side of the flat circular piece that borders the slit, 
 the recess and the enlargement inhibiting separation of the flat circular piece, wherein the enlargement has a dimension larger than a dimension of the recess such that the enlargement is unable to pass through a front end of the recess. 
 
 
 
     
     
       2. The grommet according to  claim 1 , wherein:
 a diameter-direction concavity is provided on the flat circular piece of the silencer so as to segment the flat circular piece; 
 annular ribs which are tightly fitted to the inner peripheral surface of the large diameter tubular portion of the grommet are provided on the outer peripheral surface of the flat circular piece segmented by the concavity; 
 the wire harness insertion hole is provided eccentrically in an eccentric position in a first half-circle portion segmented by the concavity; 
 the slit is orthogonal to the concavity and is extended into a second half-circle portion; and 
 the irregularly shaped line portion is provided in the second half-circle portion. 
 
     
     
       3. The grommet according to  claim 2 , wherein:
 the silencer includes a small diameter tubular portion protruding from the peripheral edge of the wire harness insertion hole; 
 an extended slit continuous with the slit is provided in the small diameter tubular portion of the silencer in an axial line direction; and 
 the small diameter tubular portion of the silencer is fitted within the small diameter tubular portion of the grommet. 
 
     
     
       4. The grommet according to  claim 1 , wherein:
 the silencer includes a small diameter tubular portion protruding from the peripheral edge of the wire harness insertion hole; 
 an extended slit continuous with the slit is provided in the small diameter tubular portion of the silencer in an axial line direction; and 
 the small diameter tubular portion of the silencer is fitted within the small diameter tubular portion of the grommet. 
 
     
     
       5. The grommet according to  claim 1 , wherein the enlargement comprises a circular portion and a narrow extending portion integrally connecting the circular portion to the second opposing side of the flat circular piece. 
     
     
       6. The grommet according to  claim 1 , wherein the enlargement comprises a dovetail shaped portion.